Controlling aflatoxins in maize in Africa: strategies, challenges and opportunities for improvement

Authors: AYALEW, AMARE - Partnership For Aflatoxin Control In Africa, Ethiopia; KIMANYA, MARTIN - Partnership For Aflatoxin Control In Africa, Ethiopia; MATUMBA, LIMBIKANI - Lilongwe University Of Agriculture And Natural Resources; BANDYOPADHAYAY, RANAJIT - International Institute Of Tropical Agriculture (IITA); MENKIR, ABEBE - International Institute Of Tropical Agriculture (IITA); Cotty, Peter

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 7/1/2017
Publication Date: 7/31/2017
Citation: Ayalew, A., Kimanya, M., Matumba, L., Bandyopadhayay, R., Menkir, A., Cotty, P.J. 2017. Controlling aflatoxins in maize in Africa: strategies, challenges and opportunities for improvement. In: Watson, D., editor. Achieving Sustainable Cultivation of Maize Cultivation Techniques, Pest, and Disease Control. Volume 2. Cambridge, UK: Burleigh Dodds Science. p. 1-24.
DOI: https://doi.org/10.19103/AS.2016.0002.23

Interpretive Summary: Maize (Zea mays) is the most important food staple in sub-Saharan Africa (SSA), accounting for up to 70% of the total human calorific intake (Byerlee and Hiesey, 1996; Martin et al., 2000). In southern Africa, per capita annual consumption of maize remains well over 100 kg, with countries such as Malawi and South Africa being reported to have reached as high as 181 kg and 195 kg, respectively (CIMMYT, 1999). Trends indicate that the production and consumption of maize in Africa will continue to grow in the next couple of decades (Wu et al., 2011). Unfortunately, maize is subjected to pre- and post-harvest contamination with aflatoxins,which are acutely toxic, immunosuppressive, mutagenic, teratogenic and carcinogenic. (Williams et al., 2004). Aflatoxins are produced mainly by some strains of the related species, Aspergillus flavus and A. parasiticus. In east Africa, consumption of such heavily contaminated maize has been the cause of acute outbreaks of aflatoxin poisoning, which caused hundreds of deaths (Probst et al., 2007). Chronic exposure to aflatoxins has been reported to lead to malnutrition and stunted growth in children and to many other disabilities (Gong et al., 2004; Khlangwiset et al., 2011). There are reports showing that aflatoxins increase the rate of progression from HIV infection to AIDS (Jolly et al., 2013; Jolly, 2014). Considering the heavy dietary reliance on maize in Africa, the associated exposure of the population to aflatoxins is high. Aflatoxin contamination of maize also limits trade and value addition through processing by food and feed manufacturers. The best approach is prevention, both in the field and during storage, and strategies for control have been discussed earlier (Bruns, 2003; Chulze, 2010). However, environmental conditions and socio-economics in Africa are complex, requiring a tailored strategy. This chapter discusses options and interventions for aflatoxin control and management in maize in the continent, the associated challenges and opportunities for improvement.

Technical Abstract: Maize (Zea mays) is the most important food staple in sub-Saharan Africa (SSA), accounting for up to 70% of the total human calorific intake (Byerlee and Hiesey, 1996; Martin et al., 2000). In southern Africa, per capita annual consumption of maize remains well over 100 kg, with countries such as Malawi and South Africa being reported to have reached as high as 181 kg and 195 kg, respectively (CIMMYT, 1999). Trends indicate that the production and consumption of maize in Africa will continue to grow in the next couple of decades (Wu et al., 2011). Unfortunately, maize is subjected to pre- and post-harvest contamination with aflatoxins,which are acutely toxic, immunosuppressive, mutagenic, teratogenic and carcinogenic. (Williams et al., 2004). Aflatoxins are produced mainly by some strains of the related species, Aspergillus flavus and A. parasiticus. In east Africa, consumption of such heavily contaminated maize has been the cause of acute outbreaks of aflatoxin poisoning, which caused hundreds of deaths (Probst et al., 2007). Chronic exposure to aflatoxins has been reported to lead to malnutrition and stunted growth in children and to many other disabilities (Gong et al., 2004; Khlangwiset et al., 2011). There are reports showing that aflatoxins increase the rate of progression from HIV infection to AIDS (Jolly et al., 2013; Jolly, 2014). Considering the heavy dietary reliance on maize in Africa, the associated exposure of the population to aflatoxins is high. Aflatoxin contamination of maize also limits trade and value addition through processing by food and feed manufacturers. The best approach is prevention, both in the field and during storage, and strategies for control have been discussed earlier (Bruns, 2003; Chulze, 2010). However, environmental conditions and socio-economics in Africa are complex, requiring a tailored strategy. This chapter discusses options and interventions for aflatoxin control and management in maize in the continent, the associated challenges and opportunities for improvement.